DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Arguments
Applicant's arguments filed 1/30/2026 have been fully considered but they are not persuasive. The circularity of the small silica particles has been amended to a range of 0.88 to 0.91. Applicant argues that Yamagishi strongly teaches that the silica should have a circularity of 0.92 to 0.98 in order to improve transferability. However, Yamagishi teaches that the circularity of the silica particles may be 0.90 to 1.00 ([0080] line 1-2). MPEP 2144.05 states, In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990) (The prior art taught carbon monoxide concentrations of "about 1-5%" while the claim was limited to "more than 5%." The court held that "about 1-5%" allowed for concentrations slightly above 5% thus the ranges overlapped.); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997) (Claim reciting thickness of a protective layer as falling within a range of "50 to 100 Angstroms" considered prima facie obvious in view of prior art reference teaching that "for suitable protection, the thickness of the protective layer should be not less than about 10 nm [i.e., 100 Angstroms]." The court stated that "by stating that ‘suitable protection’ is provided if the protective layer is ‘about’ 100 Angstroms thick, [the prior art reference] directly teaches the use of a thickness within [applicant’s] claimed range."). See also In re Bergen, 120 F.2d 329, 332, 49 USPQ 749, 751-52 (CCPA 1941) (The court found that the overlapping endpoint of the prior art and claimed range was sufficient to support an obviousness rejection, particularly when there was no showing of criticality of the claimed range). Further, exemplary silica particle 4, a smaller sized silica particle with a diameter of 65 nm, has a circularity of 0.913 (Table 3). This is very similar to the small size-side silica particle in example 3 of the instant application, which has a diameter of 70 nm and a circularity of 0.91 (Tables 3 & 4).
Applicant argues that the modified toner of Yamagishi and Matsuo would not have the same coverage rates of the external additives as the toner of the instant application as the particle shape of the silica (circularity of 0.88-0.91) is not the same. While coverage rates are dependent on multiple factors as discussed by the Applicant, there is enough overlap of conditions that Expression (1) would be expected to be satisfied. As discussed above, Yamagishi teaches a circularity for the silica particle of 0.90 to 1.00 ([0080]), and discloses an exemplary silica particle with a circularity of 0.913 (Table 3). The strontium titanate particles of Yamagishi ([0236]) are also identical to those of the instant application ([0158]). Therefore, the shape of the silica particles, the size of the silica particles, the amount of silica added, the amount and type of strontium titanate particles, the surface of the toner particles, and the method of the addition of the particles to the surface of the toner are all the same. Given all of these factors, the coverage rates of the particles would be expected to be very close to the coverage rates of the instant application.
As an example, the coverage rate of the strontium titanate particles in example 1 of the instant application is 15% (Table 4). This would be the same as Yamagishi, as the strontium titanate and toner particles are the same as the instant application. In order for the result of Expression (1) to be 0.1, the coverage of the small-sized silica particles would have to be 135%. In order for the result of Expression (1) to be 0.9, the coverage of the small sized silica would have to be 1.7%.
15
(
15
+
B
)
=
0.1
→
B
=
15
0.1
-
15
=
135
15
(
15
+
B
)
=
0.9
→
B
=
15
0.9
-
15
=
1.7
In order for the coverage rate of the silica to be either 1.7% or 135% there would have to be a significant difference in the silica particle, addition amount, or method of addition. Therefore, the relationship between the coverage rate A of the strontium titanate and the coverage rate B of the small-sized silica would satisfy 0.2 ≤ A/(A+B) ≤ 0.8.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1, 2, and 4-16 are rejected under 35 U.S.C. 103 as being unpatentable over Yamagishi (European Patent Application No. 3435166) in view of Matsuo (European Patent Application Publication No. 3379334).
Yamagishi teaches an electrostatic charge image developing toner comprising toner particles, silica particles, and titanic acid compound particles (strontium titanate) (Abstract). The silica particles may be monodispersed or polydispersed ([0070]). The monodispersed large diameter silica particles have a primary particle diameter of 90 nm or more and 160 nm or less ([0072-73]). The polydispersed silica particles have an average primary particle diameter of 50 nm or more and 180 nm or less ([0077]). The average circularity of the silica particles is 0.90 to 1.00 ([0080]).
The strontium titanate particles have a particle diameter of 30 nm or more and 60 nm or less ([0091]) and a circularity of 0.86 to 0.92 ([0103]). The strontium titanate particles are doped with a metal element ([0110]), preferably lanthanum ([0112]). The difference between the circularity of the silica particles and the strontium titanate particles is 0.15 or less, as a larger difference causes electrostatic repulsive forces between the particles, and the distribution of the particles would be uneven ([0083]). In examples 46 and 47, the difference between the circularity of the exemplary strontium titanate particle (1), circularity of 0.880, and exemplary small silica particle (4), circularity of 0.913, is 0.033 (Table 3).
Yamagishi teaches an electrostatic charge image developer comprising the toner ([0174]). The image forming method and image forming apparatus comprise an image holder, a charging unit that charges the surface of the image holder, an electrostatic charge image forming unit that forms an electrostatic charge image on the charged surface of the image holder, a developing unit that contains the developer, and develops the charge image as a toner image, a transfer unit that transfers the toner image to the surface of a recording medium, and a fixing unit that fixes the toner image to the recording medium ([0181-182]). The image forming apparatus includes a process cartridge that includes a developing unit that contains the developer, wherein the cartridge is attachable to and detachable from the image forming apparatus ([0185]). The toner cartridge comprises a container that contains the toner, wherein the cartridge is attachable to and detachable from the image forming apparatus ([0214]).
Yamagishi teaches that the silica particles may be polydispersed silica particles obtained by mixing monodispersed silica particles ([0070]), but is silent regarding two distinct silica particles having, in a number-based primary particle size distribution curve, a small size-side peak in a range of 20 nm or more and 80 nm or less, and a large size-side peak in a range of 80 nm or more and 130 nm or less.
Matsuo teaches a toner comprising toner particles and inorganic fine particles on the surface of the toner particle, wherein the particle diameter numerical distribution of the inorganic fine particles has a peak A1 and B1 present in specific particle diameter ranges (Abstract). The inorganic fine particles are preferably silica fine particles ([0032]). The peak A1 is at a particle diameter of at least 35 nm, and not more than 55 nm ([0020]). A half-width of the peak is not specified, but absent any evidence to the contrary, it can be assumed the particle size distribution is small, and the half-width of the peak would be 25 nm or less. Matsuo teaches that the number of particle with a particle diameter of 5 to 30 nm is not more than 10 number%, and preferably not more than 7 number% ([0025]). In order to prevent a large number of particle with a diameter in the range of 5 to 30 nm, the half-width of the peak must be small, as the peak A1 may be 35 nm.
The peak B1 is at a particle diameter of at least 80 nm and not more than 135 nm ([0022]). As all of the silica particles are produced in a similar manner ([0126-127]), the large silica particle would also be expected to have a small half-width. Matsuo does not specify a valley between the peaks, but considering that peak A1 is in a range of 35 to 55 nm, peak B1 is in a range of 80 to 135 nm, and the peaks do not have a wide size distribution, a valley would be present between the peaks. Exemplary toners 1-10 contain silica fine particles A1 and silica fine particles B1, which have peak values at 40 nm and 100 nm, respectively (Tables 1 & 2). The difference in particle size between the small size-side peak and the large size-side peak in the primary particle size distribution of the silica particle for these examples is 60 nm.
A toner with the inorganic fine particles wherein the particle diameter numerical distribution of the primary particle has a peak A1 in a range of 30 to 55 nm and a peak B1 in a range of 80 to 135 nm has the benefits of flowability of the toner and developer, even during ling-term use, the stress resistance is enhanced, and a high-quality image is obtained ([0016-17]). By using the particles with the specified diameter ranges, the small-diameter particle restricts the movement of the large-diameter particle, improving the durability of the toner ([0019]). The small particles in the range of 35 to 55 nm are large enough to not und up completely buried in the surface of the toner, allowing flowability to be maintained, but are small enough to not produce streaks when stress is applied ([0020]). The large particles in a range of 80 to 135 nm are large enough to maintain flowability after having stress applied, but small enough that the particles will remain fixed to the toner and will not contaminate the carrier ([0022]). Therefore, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention to have modified the toner of Yamagishi to have included the inorganic fine particles with two particle diameter numerical distribution peaks of Matsuo as the polydispersed silica particles in order to achieve better flowability, stress resistance, and image quality.
The silica particles of Matsuo do not specify a circularity, but in selecting the silica particles of Matsuo as the polydispersed silica particles of Yamagishi it is advantageous to use the circularity of the silica particles that Yamagishi teaches, as the circularities of the silica and strontium titanate particles relate to each other in order to maintain the transferability of the toner. The difference in the circularity of the silica particle and the circularity of the strontium titanate particle is 0.15 or less, as in a case with a larger difference there are large electrostatic repulsive forces between the particle, causing uneven distribution ([0083]). Therefore, it would have been obvious to a person of ordinary skill in the art to have applied the circularity of the silica particles of Yamagishi to the silica particles of Matsuo in order to prevent unwanted electrostatic repulsive charges between the particles.
In the modified toner, the difference between the particle size of the strontium titanate and the small size silica particles would be 20 nm or less. Strontium titanate particles 1, 3, and 4 have diameters of 50, 25, and 40 nm, respectively (Yamagishi, Table 1). Using silica fine particles A1 with a diameter of 40 nm of Matsuo, the difference would be 10, 15, and 0 nm, respectively. In a number based primary particle size distribution curve of the mixed particles of the strontium titanate and silica particles, the mixed particles would have a first peak with a maximum value between 25 and 50 nm for the strontium titanate and small silica particles, as their values are close enough to form one peak, and a second peak in a range of 80 to 135 nm for the large silica particles. The difference between the particle size of the strontium titanate particles 1 and 4 and the large silica fine particles B1 would be 50 and 60 nm, respectively. Yamagishi and Matsuo are both silent regarding the coverage of the additives with respect to the toner particles. However, Yamagishi teaches the same toner particles as the toner of the instant application ([0217-225]) and additions of 2 parts of the silica particles and 1 part of the strontium titanate particles for 100 parts of the toner particles, mixing for 15 minutes at a speed of 30 m/sec ([0251]). This is the same procedure for external addition as the toner of the instant application, so it would be assumed that the coverage rates of the particles would be the same. Therefore, Expression (1), 0.2 ≤ A/(A+B) ≤ 0.8, and Expression (2), 10 ≤ A+B ≤ 50, would be satisfied, and the large silica particles would have a coverage of 20% or more and 40% or less.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Jenna Kuipers whose telephone number is (571)272-0161. The examiner can normally be reached Monday - Friday 8:30 - 5:30 PT.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jonathan Johnson can be reached at 571-272-1177. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/J.K./Examiner, Art Unit 1734
/PETER L VAJDA/Primary Examiner, Art Unit 1737 04/20/2026
Prosecution Insights